This invention relates to an improved tree harvesting device and, particularly, to an improved arrangement for cutting branches and limbs from tree trunks. While a number of devices have been employed for this purpose, their use has not been without difficulty. For example, the typical type of device employs a chain-like member which is wrapped about the tree trunk and then the trunk is moved axially through the chain to sever the limbs and branches.
One of the difficulties which often is encountered results from the tendency of trees to grow a plurality of branches or limbs at the same location along the length of the trunk in a "crown-like" array. With the typical prior devices, the cutting chain is arranged so that it will engage all of the branches at a particular location along the length of the trunk at or about the same time. This necessitates the use of extremely heavy equipment in order to be able to cut the plurality of branches or limbs at or about substantially the same time. Also among the difficulties encountered with the prior devices is that many of them do not employ a single chain which entirely surrounds the tree to be stripped but, instead, includes a plurality of additional stripping devices, which results in a more complex, awkward and heavier type of equipment.
The above difficulties are overcome with the present invention which employs a single cutting chain formed from a plurality of articulated links, one end of the chain being pivoted to a frame and the other end of a pivoting arm which can be operated to wind or unwind the chain about the tree trunk. The chain is longer than the circumference of the tree trunk and is arranged so that when it is wrapped about the tree trunk, it will assume a helical configuration. To this end, the pivoting arm is located in longitudinally spaced relation to the connection of the first mentioned end of the chain to the frame. When the tree trunk is advanced axially through and with respect to the helically wound chain, the limbs or branches will be severed one at a time, even at a crown region of the trunk, where a plurality of limbs may extend outwardly from the same location on the trunk. Because the limbs are severed individually, substantially less power is required and the equipment need not be as heavy as has been the practice with the prior devices.
It is among the objects of the invention to provide an improved tree delimbing device.
A further object of the invention is to provide an improved limb stripping device employing an articulated chain which is wrapped about the tree trunk in a helical configuration and which extends more than 360.degree. about the trunk.
Another object of the invention is to provide a delimbing device which can sever a plurality of limbs extending from the trunk in a crown-like configuration without requiring extraordinarily heavy equipment.
A further object of the invention is to provide a delimbing device of the type described in which, when the helically disposed chain is unwrapped, the articulated chain links are precluded from being unwrapped beyond a straight configuration.
Another object of the invention is to provide an improved delimbing chain formed from a plurality of articulated links connected to circumscribe the tree trunk helically, the articulated links each carrying a generally parallelogram-shaped cutting blade.